Amorphous metallic and nitrogen containing alloy films

Abstract

These amorphous metal-alloy films include nitrogen, greater than about one atomic percent at least one transition metal selected from Cr, Fe, Co and Ni with at least one element forming an amorphous alloy therewith, selected from the "glass forming" elements, i.e., B, Si, Al, C and P. The alloys can be formed by deposition in a vacuum chamber. When films are sputtered, the target is composed of the above alloy elements with at least one element selected from each of the transition metal and glass forming element groups. Sputtering occurs in an atmosphere above about 2% vol. N 2 gas mixed with an inert gas, e.g., Ar. Alloys produced include N, i.e., (Co-Fe-B)N and (Fe-B)N. Above about 2 atomic % N in the film, films have lower values of saturation magnetization 4πM s . Above a 2% vol. N 2 gas in the plasma, electrical resistivity increases. Over 0.5% vol. N 2 gas in the plasma, the film's effective perpendicular anisotropy field H k * increases. For (Co-Fe-B)N, the anisotropy direction moves from in plane to perpendicular above 2% vol. N 2 plasmas. For (Fe-B)N, H k * increases with N 2 up to 10% vol. N 2 plasma. The N% in a film varies linearly with the log of N 2 % vol. Films show markedly improved adhesion, corrosion resistance and hardness. Magnetic thermal stability increases with N 2 above about 5% vol. N 2 in a plasma. Structural and magnetic properties are stable for annealing up to 400° C.

What is claimed is: 
     
       1. An amorphous metallic alloy film composed of nitrogen with at least one transition metal selected from the group consisting of Cr, Fe, Co, and Ni and with at least one element selected from the group consisting of B, Si, Al, C, and P, wherein the nitrogen content of said alloy is greater than about 1 atomic percent. 
     
     
       2. A film in accordance with claim 1 wherein said film comprises an alloy of (Co-Fe-B)N. 
     
     
       3. A film in accordance with claim 2 wherein said film comprises (C0 78  Fe 5  B 17 ) x  N 100-x  where 100-x is at least about 1% of x. 
     
     
       4. A film in accordance with claim 1 wherein said film comprises an alloy of (Fe-B)N. 
     
     
       5. A film in accordance with claim 4 wherein said film comprises an alloy of (Fe 80  B 20 ) x  N 100-x  where 100-x is at least about 1% of x. 
     
     
       6. A film in accordance with claim 1 wherein said film is deposited upon a substrate and said film possesses an adhesion to said substrate exceeding a pull test in which a rigid object is secured to said film with an epoxy glue and the substrate and the rigid object are pulled to a force reaching the destruction limit of said substrate and said film contains on the order of 26 atomic percent of nitrogen. 
     
     
       7. A film in accordance with claim 1 wherein said film is deposited upon a substrate and said film possesses an adhesion to said substrate exceeding a peeling test with adhesive tape wherein said tape is applied to said film and pulled away from said substrate and said film contains about 14 to 26 atomic percent of nitrogen. 
     
     
       8. A film in accordance with claim 1 wherein said film possesses a hardness having an increase of 1 grade on the Moh's scale above the hardness of a comparable alloy excluding any nitrogen, and said film includes in the order of 20 atomic percent of nitrogen. 
     
     
       9. A film in accordance with claim 1 wherein said film has magnetic-thermal stability up to 400° C. and said film includes above about 9 atomic percent of nitrogen. 
     
     
       10. A film in accordance with claim 1 having corrosion resistance containing greater than about 10 atomic percent of an element selected from the group consisting of chromium and nitrogen wherein said nitrogen is in addition to said 1 atomic percent for a total greater than about 10 atomic percent. 
     
     
       11. A film in accordance with claim 1 having a substantial perpendicular anisotropy including more than about 1 atomic percent of nitrogen in the film. 
     
     
       12. A film in accordance with claim 1 wherein an alloy including one or more elements selected from the group of magnetic transition metals consisting of Fe, Ni and Co in substantial quantities sufficient to have a high magnetization in the absence of nitrogen in the film but which has substantially no magnetization when the atomic percent of nitrogen in the film is on the order of 20.